A dust filter electrode is known which is formed of a pair of .omega.-section straight metal channels which are fitted together, concave sides toward each other, with their flat flanges coextensively contacting one another. The hollow core so formed is fitted at regular intervals with laterally extending metallic arms whose ends are frequently split and bent in opposite directions.
It is customary to form such an electrode simply by manually juxtaposing two channel sections of the desired length, then manually spot welding individual preformed arms to the flanges of the core so formed at the desired intervals. It is absolutely essential that the electrodes be perfectly straight and uniform. Such manual manufacture is an extremely expensive and painstaking process. Since it is often necessary to produce electrodes having a length of 12 meters or more, the fabrication process can take up a great deal of space, often requiring a work table and jig that is immense.